Phytochemical investigation on the aerial parts of Trachelospermum dunnii led to the isolation and identification of 16 compounds, including nine dibenzylbutyrolactone lignans (1–9), two furanoid ...lignans (10–11), one dihydrobenzofuran lignan (12), one aryltetralin lignan (13), two flavonoids (14–15), and one phenolic compound (16). The structure of compound 1 was elucidated by means of spectroscopic analyses, including HRESIMS, and 1D and 2D NMR experiments. Compounds 1–16 are reported from title plant for the first time, while compounds 1–2, 10–12, and 14–16 have not been recorded previously in genus Trachelospermum. The dibenzylbutyrolactone lignans may serve as chemotaxonomic markers of T. dunnii.
•Sixteen metabolites are isolated from Trachelospermum dunnii (H.Lév.) H. Lév.•Compounds 1–16 are first time isolated from the species Trachelospermum dunnii.•Compounds 1–2 and 9–16 are the first report from the genus Trachelospermum.•Dibenzylbutyrolactone lignans could be considered as chemotaxonomic markers for genus Trachelospermum.
Enhancing both the humoral and cellular immune response for tumor vaccination remains a challenge. Inspired by natural pathogen structures, we took β-glucan particles derived from a baker's yeast ...cell shell (YS) as a vaccine carrier and danger signal for dendritic cells (DCs), and coated the YS with catanionic layered double hydroxides (LDH) by electrostatic adsorption to form a biomimetic yeast cell particle (YSL). Our experimental results showed that the YSL vaccine efficiently targeted antigen-presenting cells (APCs) and remarkably enhanced antigen cross-presentation, and strongly improved the activation and maturation of DCs. Moreover, the YSL vaccine elicited an extremely high antibody titer and strong antigen-specific cytotoxic T lymphocyte together with mixed Th1/Th17 cellular immune responses and induced marked prophylactic and therapeutic effects against E.G7-OVA tumors in mouse models. These results suggest that YSL, integrating a yeast shell to mimic natural pathogens and LDH with high antigen-loading capacity and lysosome escape, is a promising tumor vaccine platform for rapid, effective and strong induction of both humoral and cellular immune responses.
Schematic illustration of the LDH nanoparticle-coated yeast shell vaccine and immune activation.
An asymmetric synthesis of 14-methyl-1-octadecene, the sex pheromone of the peach leafminer moth has been achieved. The target molecule was synthesized in six linear steps and in 30.3% overall yield ...from commercially available hexanoyl chloride, (S)-4-benzyloxazolidin-2-one and 1,9-nonanediol. The hexanoyl chloride was connected with (S)-4-benzyloxazolidin-2-one, and with the induction of the chiral oxazolidinone auxiliary, after chiral methylation, LAH reduction and then tosylation gave the chiral key intermediate 5 in high stereoselectivity. 1,9-Nonanediol, was selectively brominated, THP protected and subjected to Li₂CuCl₄-mediated C-C coupling to afford a C12 intermediate. The target molecule, (S)-14-methyl-1-octadecene, was obtained after the two parts were subjected to a second Li₂CuCl₄-mediated C-C coupling. Our synthetic approach represents the first time a substrate-control asymmetric synthesis of (S)-14-methyl-1-octadecene has been reported.
Phytochemical investigation on the ethyl acetate fraction of the leaves of Epigynum cochinchinensis led to the isolation of a new C
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pregnane glycoside, epigycoside B (1), together with three known ...analogues. Their structures were elucidated on the basis of extensive spectroscopic techniques, including UV, MS, and NMR experiments, as well as the chemical methods. Compound 1 displayed in vitro immunosuppressive activity against concanavalin A (Con A)/Lipopolysaccharides (LPS)-stimulated proliferation of mice splenocyte. The activity was significant as compared with control group at 50 μM concentration.
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RRR-α-tocopherol quinone (α-TQ), a main derivative of α-T, could inhibit Aβ42 fibril formation dose-dependently, disaggregate preformed fibrils and interfere with natural intracellular Aβ oligomer ...formation. ▶ Alpha-TQ attenuated Aβ42-induced neurotoxicity toward SH-SY5Y neuroblastoma cells by decreasing the formation of reactive oxygen species (ROS) and NO. ▶ Moreover, α-TQ modulated the production of cytokines by decreasing TNF-α and IL-1β and increasing IL-4 formation in microglia.
Alzheimer's disease (AD) is a complex, multifactorial neurodegenerative disease. The aggregation of beta-amyloid (Aβ) into extracellular fibrillar deposition is a pathological hallmark of AD. The Aβ aggregate-induced neurotoxicity, inflammatory reactions and oxidative stress are linked strongly to the etiology of AD. The currently available hitting-one-target drugs are insufficient for the treatment of AD. Therefore, finding multipotent agents able to modulate multiple targets simultaneously is attracting more attention. Previous studies indicated that vitamin E or its constituent such as α-tocopherol (α-T) was able to attenuate the effects of several pathogenetic factors in AD. However, ineffective or detrimental results were obtained from a number of clinical trials of vitamin E. Here, we showed that naturally synthesized
RRR-α-tocopherol quinone (α-TQ), a main derivative of α-T, could inhibit Aβ42 fibril formation dose-dependently. Further investigations indicated that α-TQ could attenuate Aβ42-induced neurotoxicity toward SH-SY5Y neuroblastoma cells, disaggregate preformed fibrils and interfere with natural intracellular Aβ oligomer formation. Moreover, α-TQ could decrease the formation of reactive oxygen species (ROS) and NO, and modulate the production of cytokines by decreasing TNF-α and IL-1β and increasing IL-4 formation in microglia. Taken together, α-TQ targeting multiple pathogenetic factors deserves further investigation for prevention and treatment of AD.
•A direct high-flow pAVF which supplied by the trunk of left ACA and left PCA and drained into the vein of Galen.•The direct high-flow pAVF underwent microsurgical complete clip in one stage.
Pial ...arteriovenous fistula (pAVF) is a rare intracranial vascular lesion. In pAVF, there is direct connection between one or more arterial supply and venous drainage without intervening nidus. We present a case of pAVF with multiple fistulous points and vein of Galen dilation which underwent microsurgical complete clip in one stage.
Paraquat (PQ) is an efficient herbicide but leads to high mortality with no antidote in mammals. PQ produces reactive oxygen species (ROS), leading to epithelial-mesenchymal transition (EMT) for ...pulmonary fibrosis in type II alveolar (AT II) cells. Intriguingly, strategies reducing ROS exhibit limited therapeutic effects, indicating other targets existing for PQ toxicity. Herein we report that PQ is also an agonist for STIM1 that increases intracellular calcium levels. Particularly, PQ promotes STIM1 puncta formation and association with TRPC1 or ORAI for extracellular calcium entry and thus intracellular calcium influx. Further studies reveal the importance of P584&Y586 residues in STIM1 for PQ association that facilitates STIM1 binding to TRPC1. Consequently, the STIM1-TRPC1 route facilitates PQ-induced EMT for pulmonary fibrosis as well as cell death. Our results demonstrate that PQ is an agonist of STIM1 that induces extracellular calcium entry, increases intracellular calcium levels, and thus promotes EMT in AT II cells.
We herein report our investigation into the effect of the filter layer thickness on the filtration performance of dual layer granular bed filters using an experimental granular bed filter with an ...inner diameter of 100 mm and employing fly ash as the example dust. It was found that increasing the thickness of the upper filter layer from 180 to 280 mm reduced the average outlet dust concentration of the dual layer granular bed from 8.69 to 6.57 mg/m3, in addition to prolonging the time between regeneration cycles from 43.3 to 56 min, and increasing the pressure drop across the bed from 1873 to 1978 Pa. Furthermore, increasing the thickness of the lower filter layer from 45 to 85 mm reduced the average outlet dust concentration of the dual layer granular bed from 8.69 to 3.94 mg/m3 and extended the time between regeneration cycles from 43.3 to 59 min. However, this also resulted in an increased pressure drop across the filter from 1935 to 3077 Pa. These results indicated that an increase in the thickness of the upper filter layer reduced outlet dust concentrations and extended the regeneration cycles, without having a significant impact on the total pressure drop across the dual layer granular bed. Although an increase in the thickness of the lower filter layer significantly reduced outlet dust concentrations, the pressure drop across the dual layer granular bed filter was greatly increased in this case.
Fig. 2 Schematic representation of the dual layer granular bed filter employed herein. Display omitted
•Filter layer thickness affected the performance of dual layer granular bed filters.•An increase in the upper filter layer thickness reduced outlet dust concentrations.•An increase in the lower filter layer thickness reduced outlet dust concentrations.•Upper filter layer thickness has less effect on bed pressure drop.•Lower filter layer thickness has a great influence on bed pressure drop.
Based on solid solution theory, mass conservation law and classical nucleation, growth and coarsening theory, a thermo/kinetic model is developed to predict the precipitation behavior of complex ...precipitates in Nb‐V bearing steel. The equilibrium composition of matrix and precipitates is calculated by the thermodynamic model and is input in the kinetic model to calculate the driving force for precipitation at a given temperature. The diffusivity and concentration of alloying elements is considered in the entire precipitation process. The effect of interfacial energy of precipitates and activation energy on precipitation behavior are studied. Simulation results indicate that the interfacial energy plays a significant role in the entire process of precipitation and there is no overlap between nucleation and coarsening when the interfacial energy is in the range of 0.5–0.55 Jm−2. The mean particle diameter predicted by the proposed model is compared with the experimental results and a good agreement was obtained.
A thermo/kinetic model is developed to predict the precipitation behavior of complex precipitates in Nb‐V bearing steel. The diffusivity and the concentration of alloying elements are considered in the entire precipitation process. The effect of interfacial energy of precipitate on precipitation behavior is studied. The mean particle diameter predicted by the proposed model agrees well with the experimental results.
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